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llvm-mirror/test/Transforms/IndVarSimplify/preserve-signed-wrap.ll
Dan Gohman 1d93a1d2cb Back out the change in 64918 that used sign-extensions when promoting
trip counts that use signed comparisons. It's not obviously the best
approach for preserving trip count information, and at any rate there
isn't anything in the tree right now that makes use of that, so for
now always using zero-extensions is preferable.

llvm-svn: 65347
2009-02-23 23:20:35 +00:00

39 lines
1.2 KiB
LLVM

; RUN: llvm-as < %s | opt -indvars | llvm-dis > %t
; RUN: grep sext %t | count 1
; RUN: grep phi %t | count 1
; RUN: grep {phi i64} %t
; Indvars should insert a 64-bit induction variable to eliminate the
; sext for the addressing, however it shouldn't eliminate the sext
; on the other phi, since that value undergoes signed wrapping.
define void @foo(i32* nocapture %d, i32 %n) nounwind {
entry:
%0 = icmp sgt i32 %n, 0 ; <i1> [#uses=1]
br i1 %0, label %bb.nph, label %return
bb.nph: ; preds = %entry
br label %bb
bb: ; preds = %bb1, %bb.nph
%i.02 = phi i32 [ %5, %bb1 ], [ 0, %bb.nph ] ; <i32> [#uses=2]
%p.01 = phi i8 [ %4, %bb1 ], [ -1, %bb.nph ] ; <i8> [#uses=2]
%1 = sext i8 %p.01 to i32 ; <i32> [#uses=1]
%2 = sext i32 %i.02 to i64 ; <i64> [#uses=1]
%3 = getelementptr i32* %d, i64 %2 ; <i32*> [#uses=1]
store i32 %1, i32* %3, align 4
%4 = add i8 %p.01, 1 ; <i8> [#uses=1]
%5 = add i32 %i.02, 1 ; <i32> [#uses=2]
br label %bb1
bb1: ; preds = %bb
%6 = icmp slt i32 %5, %n ; <i1> [#uses=1]
br i1 %6, label %bb, label %bb1.return_crit_edge
bb1.return_crit_edge: ; preds = %bb1
br label %return
return: ; preds = %bb1.return_crit_edge, %entry
ret void
}